CN104136046A - Method and apparatus for reducing biocarriers using induction heating - Google Patents

Abstract

Methods, systems, devices, and machine-readable media for reducing biological carryover are disclosed. An exemplary method includes generating an alternating electromagnetic field and introducing an aspiration and dispense device into the electromagnetic field. The exemplary method also includes inductively heating the aspiration and dispense device using the electromagnetic field to at least denature or inactivate at least one of a protein or a biological entity on a surface of the aspiration and dispense device.

Description

Method and apparatus for reducing biocarriers using induction heating

related application

This application claims priority to US Provisional Patent Application Serial No. 61/580,913, entitled "Methods and Apparatus to Reduce Biological Carryover Using Induction Heating," filed December 28, 2011, the entire contents of which are hereby incorporated by reference.

technical field

The present disclosure relates generally to medical diagnostic instrumentation, and more particularly to methods and apparatus for reducing bio-carryover using induction heating.

Background technique

Probes are used in medical diagnostic instruments to draw and/or dispense samples and reagents into and/or from sample tubes and reaction vessels. The potential for carryover or cross-contamination increases when probes are reused. Some existing methods for preventing protein cross-contamination require probe replacement. Probe replacement creates significant waste and increases operating cost and time.

Description of drawings

Figure 1 is a schematic diagram of electromagnetic induction.

2A-C illustrate exemplary aspiration and dispense devices that are inductively heated and cleaned.

3A-E illustrate another exemplary aspiration and dispense device that is inductively heated and cleaned.

4 is a schematic diagram of an exemplary configuration of an electromagnetic field generator.

5 is a schematic diagram of another exemplary configuration of an electromagnetic field generator.

6 is a schematic diagram of another exemplary configuration of an electromagnetic field generator.

7 is a schematic diagram of another exemplary configuration of an electromagnetic field generator.

8 is a flow diagram representing an example process that may be performed to implement the example systems disclosed herein.

9 illustrates an example processor platform that may be used to implement any or all of the example methods, systems, and/or devices disclosed herein.

Detailed ways

Automated medical diagnostic instruments and automated pipette systems use one or more aspiration and/or dispensing devices (such as, for example, pipettes or probes) to draw samples (such as biological samples) and/or reagents into reactions Samples and/or reagents are dispensed into and/or from said reaction vessels into and/or from said reaction vessels, such as, for example, one or more wells on a multiwell plate. The outer and inner surfaces of the aspiration and/or dispensing device are in contact with the sample and/or reagent, and a portion of the sample and/or reagent may remain on the outer and/or inner surface after the sample and/or reagent has been dispensed. Subsequent use of the aspiration and/or dispensing device can result in sample carryover or reagent carryover. Such carryover is the transfer of residual sample and/or reagents to another sample and/or reagent, which contaminates the sample and/or reagents and can lead to inaccurate analysis or diagnosis.

Some systems include a flushing station to flush the surfaces of the suction and/or dispensing devices. However, rinse stations require large amounts of rinse solution. Furthermore, any imperfections, scratches, nicks, or other imperfections or irregularities in the surface of the aspiration and/or dispensing device can harbor biological samples and/or reagents, rendering the aspiration and/or dispensing device less clean after a rinse cycle.

In other systems, electrostatic induction is used to heat the aspiration and/or dispensing device to a sterile level. Such systems generate a non-alternating potential (eg, voltage) across the aspiration and/or dispensing device via a resistor. These systems require relatively high voltages and currents, and thus increase the risk of electrical short circuits. Furthermore, these systems generally heat the entire suction and/or dispensing device and therefore cannot only locally heat and clean contaminated areas. Furthermore, electrical current flows through the aspiration and/or dispensing device in a non-uniform manner along the path of least resistance. Surface areas of suction and/or dispensing devices that include blemishes, scratches, dents, or other irregularities have a higher electrical resistance. Consequently, these areas which are particularly susceptible to bioaccumulation are subjected to less electrical current and are thus heated less than other areas of the suction and/or dispensing device. Therefore, devices that are cleaned by electrostatic induction may not be sufficient to eliminate biocarriers.

Exemplary systems, methods, and devices disclosed herein use electromagnetic induction heating to clean suction and/or dispensing devices. In examples disclosed herein, heat generated via electromagnetic induction is used to inactivate and/or denature reactive proteins and/or other biological entities on the surface of the suction and/or dispense device. Inactivation or denaturation of biological material prevents biocarryover by reducing or eliminating cross-contamination between independent reactions.

Induction heating is achieved by means of a metal coil or any other shape of continuous conductive medium sized and shaped to provide a desired heating pattern through which an electrical signal of high frequency and high current flows in accordance with Faradaic induction The law induces opposite currents in the target object (eg suction and/or dispensing device to be cleaned). The opposite current heats the aspiration and/or dispensing device and residual protein and/or other biological matter affixed thereto. Proteins and/or other biological substances are heated above a critical temperature to change the way these materials affect and bind to other objects or substances, which reduces the chance of unintended reactions. Examples disclosed herein reduce or eliminate the possibility of contamination between individual fluid movements or reactions without requiring extensive flushing, expensive coatings, or disposable probes.

Exemplary methods disclosed herein include generating an alternating electromagnetic field and introducing an aspiration and/or dispensing device into the electromagnetic field. The exemplary method also includes inductively heating the aspiration and/or dispense device with an electromagnetic field to at least denature or inactivate at least one of proteins or biological entities on a surface of the aspiration and/or dispense device.

Some examples disclosed herein include rinsing the aspiration and/or dispensing device prior to introducing the aspiration and/or dispensing device into an electromagnetic field. Additionally, some examples include rinsing the aspiration and/or dispensing device after inductively heating the aspiration and/or dispensing device using an electromagnetic field. In some examples, flushing includes flushing with a cooling flush to reduce the temperature of the aspiration and/or dispensing device. Additionally, some examples include rinsing the aspiration and dispense device during inductive heating of the aspiration and dispense device using an electromagnetic field.

Some examples disclosed herein include generating an electromagnetic field by passing an electric current through a conductive medium using a frequency based on the diameter of the suction and/or dispensing device. Additionally, some examples disclosed herein include generating an electromagnetic field by passing an electrical current through a conductive medium using a frequency based on the thickness of the housing or walls of the suction and/or dispensing device. In some examples, the conductive medium includes a coil. In other examples, the conductive medium includes any other shape of continuous conductive medium sized and shaped to provide a desired heating pattern.

In some of the disclosed examples, the aspiration and/or dispensing device is raised and/or lowered through an electromagnetic field to inductively heat the aspiration and/or dispensing device along the length of the aspiration and/or dispensing device. Additionally, in some examples, the thickness of the housing varies along the length of the suction and/or dispensing device, adjusting the frequency as the suction and/or dispensing device is raised or lowered.

In some examples disclosed herein, only a portion of the aspiration and/or dispensing device is inductively heated. In other examples, inductively heating the aspiration and/or dispensing device using an electromagnetic field includes heating the aspiration and/or dispensing device via an electrical and/or electrostatic connection without directly contacting the aspiration and dispensing device.

In some examples, generating the alternating electromagnetic field includes utilizing a standard wall electrical outlet. In addition, some of the disclosed examples include: placing the irrigation cup between the aspiration and/or dispensing device and a conductive medium (such as, for example, a coil for generating an electromagnetic field); and preventing the aspiration and dispensing device and the conductive medium from directly Access to rinse cup.

Exemplary systems disclosed herein include an electromagnetic field generator and an aspiration and/or dispensing device to be introduced into and inductively heated by the electromagnetic field. The exemplary system also includes a flush cup interposed between the electromagnetic field generator and the aspiration and dispensing device to prevent direct contact therebetween. In some exemplary systems, the aspiration and dispense device has no electrical connectors coupled to a surface of the aspiration and dispense device, and the aspiration and dispense device is electrically insulated.

Some exemplary systems also include a flusher to flush the aspiration and/or dispense device prior to introducing the aspiration and/or dispense device into the electromagnetic field and/or after inductively heating the aspiration and/or dispense device with the electromagnetic field. In some instances, the flusher flushes with a cooling flush to reduce the temperature of the aspiration and/or dispensing device.

In some embodiments, the electromagnetic field generator includes a frequency generator and a coil, and the frequency generator is used to generate a variable-frequency current flowing through the coil. Frequency is based on the diameter of the suction and/or dispensing device. Additionally, in some examples, the electromagnetic field generator includes a frequency generator and a conductive medium (e.g., a coil or any other shape of continuous conductive medium sized and shaped to provide the desired heating pattern), and the frequency generator A device is used to generate a variable frequency current flowing through a conductive medium. The frequency is based on the thickness of the housing of the suction and/or dispensing device.

Some exemplary systems include arms to raise or lower the suction and dispense device through an electromagnetic field to inductively heat the suction and/or dispense device along the length of the suction and dispense device. Some exemplary systems include a frequency generator to adjust the frequency as the suction and/or dispensing device is raised or lowered. Such frequency may be adjusted where the thickness of the housing varies along the length of the suction and/or dispensing device.

In some examples, the electromagnetic field inductively heats only a portion of the aspiration and/or dispensing device. In some examples, the aspiration and/or dispensing device is heated without directly contacting the electrical connection. In some exemplary systems disclosed herein, the surface of the aspiration and/or dispensing device is heated to denature or inactivate at least one of proteins or biological entities on the surface.

Some example systems include a controller and a feedback loop. The feedback loop provides data to the controller including one or more of frequency, impedance, presence of the suction and dispensing device in the electromagnetic field, voltage readings or current readings, and based on the data the controller changes the frequency to The strength of the electromagnetic field is varied, thereby varying the heating temperature of the suction and/or dispensing device.

Also disclosed is an exemplary tangible machine-readable medium having stored thereon instructions that, when executed, cause the machine to generate an alternating electromagnetic field and introduce the aspiration and/or dispensing device into the electromagnetic field. The exemplary instructions further cause the machine to inductively heat the aspiration and/or dispense device using an electromagnetic field to denature and/or inactivate at least one of proteins or biological entities on a surface of the aspiration and/or dispense device.

Referring now to the drawings, Figure 1 shows a schematic diagram of electromagnetic induction. As shown in FIG. 1 , the coil 100 includes a high-frequency alternating current (AC) flowing in a first direction indicated by a white arrow. The interior of the loop of the coil 100 forms the working area 102 . When current flows through the coil 100 , an alternating magnetic field 104 extends through the working region 102 and around the coil 100 . A workpiece 106 , which may represent a portion of a probe or other aspiration and/or dispensing device, for example, may be inserted into the workspace 102 . The alternating magnetic field 104 generates eddy currents in the workpiece 106 . The eddy current flows in the opposite direction to the alternating current in the coil 100, as indicated by the larger arrow. Hysteresis losses and ohmic heating increase the temperature of the workpiece 106 . The heat changes the binding properties of any proteins or other biological entities that may be present on the surface of workpiece 106 to denature and inactivate such proteins and biological entities. The above process is equally applicable to ferrous metals, non-magnetic metals and/or other conductive materials.

2A-C illustrate a portion of an exemplary system 200 to reduce biological carryover during three operations. Exemplary system 200 includes an electromagnetic field generator 202, which in this example includes a metal coil 204, such as, for example, a copper coil. The coil 204 has a first wire 206 and a second wire 208 to electrically couple the coil 204 to a power source, such as, for example, an AC power source. The interior of the coil 204 forms a work area into which one or more workpieces may be placed, as described below. As described in connection with FIG. 1, when current flows through coil 204, a magnetic field is generated and an opposing current is induced in the workpiece.

The example system 200 also includes an example flush cup 210 . In this example, rinse cup 210 is an open-ended splash vessel that may be made of, for example, glass, ceramic, plastic, electrically insulating material, and/or any other suitable non-metallic material. The rinse cup 210 includes an inlet 212 capable of introducing rinse fluid into the rinse cup 210 . System 200 also includes a pipette probe or other aspiration and/or dispensing device 214 . In this example, the aspiration and/or dispensing device 214 is a metal probe, such as, for example, stainless steel. In FIG. 2A , the aspiration and/or dispensing device 214 is located above or outside the coil 204 . Aspiration and/or dispensing device 214 includes a liquid 216, which may be, for example, a sample, a reagent, a flushing solution, or any combination thereof. In this example, the exterior surface of the aspiration and/or dispensing device 214 is contaminated with protein or biological matter 218 . Protein or biological matter 218 may adhere to scratches or other surface irregularities on the outer surface and/or to the outer surface due to hydrophobicity, ionic charge, electrostatic charge, protein adsorption, and/or surface energy.

In Figure 2B, the suction and/or dispense device 214 is lowered into the rinse cup 210 and the coil 204 is energized to generate an alternating electromagnetic field. In this example, rinse cup 210 is inserted into suction and/or dispensing device 214 to prevent direct contact therebetween. The aspiration and/or dispensing device 214 is thus remotely inductively heated using the coil 204, thereby preventing biofouling. An advantage of this configuration is that standard aspiration and/or dispensing devices (eg, probes) can be used. No electrical connectors are required to mate with the suction and/or dispensing device. Thus, the suction and/or dispensing device is electrically insulated. Electrical insulation reduces the chance of an operator receiving electric shock due to accidental (or deliberate) contact with the suction and/or dispensing device. A current is only generated in the suction and/or dispensing device when a strong alternating magnetic field is present, and only in the material of the suction and/or dispensing device. More specifically, the operator does not provide a ground path for currents generated in the workpiece (eg, suction and/or dispensing devices) because the currents are generated only within the immediate magnetic field and are in self-contained and self-contained circuits.

The current in the coil 204 generates a magnetic field which induces a current in the suction and/or dispensing device 214 . Electric current in the aspiration and/or dispensing device 214 generates heat, thereby inductively heating the aspiration and/or dispensing device 214 . In this example, the aspiration and/or dispensing device 214 may be heated to a temperature of, eg, 300° C., and cause any remaining protein and/or biological matter to coagulate, denature, and inactivate. Temperatures as low as, for example, 43°C denature some proteins. 300°C incinerates most proteins. The temperature can be raised much higher, including for example 760°C. If there are scratches or other surface deformities on the suction and/or dispensing device 214, the current is redirected around the root of the defect, which increases the local current density and thus local heat generation, and ensures that these areas are cleaned . When a crack, scratch or defect is present, the current is concentrated and directed beneath the crack, scratch or defect, causing the bottom to experience increased heating, which is where contaminants can accumulate. Liquid 216 may be dispensed from aspiration and/or dispensing device 214 prior to or during this operation.

Furthermore, in the disclosed example, the electromagnetic field inductively heats only a portion of the suction and/or dispense device 214 to improve targeted cleaning of the suction and/or dispense device 214 and does not require heating of the entire suction and/or dispense device 214. For example, only the portion of the aspiration and/or dispensing device 214 located within the working area defined by the coil 204 is heated. Some exemplary systems include arms (see FIG. 6 ) to raise or lower the aspiration and/or dispensing device 214 through an electromagnetic field to inductively heat the aspiration and/or dispensing device 214 along its length 214 different parts.

In addition, as described in more detail below, in some examples, the current flowing through the coil 204 is based on the diameter of the suction and/or dispensing device 214 portion in the working area and/or based on the suction and/or dispensing in the working area. and/or the thickness of the housing of the dispensing device 214 portion varies. In some examples, the thickness and/or diameter of the housing varies along the length of the suction and/or dispensing device 214 and the frequency of the electrical current is adjusted as the suction and/or dispensing device 214 is raised or lowered.

In some examples, there is a pre-treatment process such as, for example, a pre-rinse to clean the surfaces of the aspiration and/or distribution device 214 before it enters the working area of the coil 204 . Additionally, in some instances, there is a post-processing process, such as a post-rinse as shown in Figure 2C. In the present example, power to the coil 204 is stopped, and the operating probe flushing device floods flushing fluid 220 through the inlet 212 to flush the exterior surfaces of the aspiration and/or dispensing device 214 to remove residual protein and/or or other biological materials. The flushing fluid 220 has a relatively lower temperature to reduce the temperature of the aspiration and/or dispensing device 214, thereby returning the temperature of the aspiration and/or dispensing device to, for example, ambient temperature. After the operation of Figures 2B and/or 2C, the aspiration and/or dispensing device 214 is ready to be used again.

3A-E illustrate another exemplary aspiration and/or dispense device 300 that is inductively heated and irrigated. Aspiration and/or dispensing device 300 is used to transport sample or reagent 302 (Fig. 3A). The exterior and interior surfaces of the aspiration and/or dispense device 300 include contaminants 304 (Fig. 3B). In some examples, aspiration and/or dispensing device 300 is flushed to remove contaminants 304, and aspiration and/or dispensing device 300 is placed in the center of coil 306 (FIG. 3C). The interior of the aspiration and/or dispensing device 300 may also be cleaned, but residual contamination 308 may remain (FIG. 3D). Although FIGS. 3B-D illustrate the aspiration and/or dispensing device 300 within the coil 306 to clean the device 300 during the pre-rinse steps and aspiration/dispensing, these processes or operations may occur while the aspiration and/or dispensing Device 300 prior to insertion into coil 306 .

An alternating current is passed through the coil 306 ( FIG. 3D ), which generates a magnetic field that induces eddy currents in the suction and/or dispense device 300 . The eddy currents generate heat, as disclosed above, to denature and inactivate any contaminants on and/or in the aspiration and/or dispensing device 300 . In some embodiments, a post-rinse treatment is provided to remove carbonized protein 310 ( FIG. 3E ) or otherwise inactivate and/or detach protein 310 that may remain in the fluid channel and/or cool the aspiration and/or Or dispensing device 300 .

FIG. 4 illustrates an exemplary circuit configuration of an electromagnetic field generator 400 that may be included, for example, in a medical diagnostic system or in a laboratory automation instrument such as an automated pipetting system. Examples include mains power supply 402 . In this example, main power supply 402 is the same power supply used for the entire medical diagnostic system. Therefore, the line voltage and frequency of the main power supply 402 is the same as used by the rest of the system, and as received from a standard wall outlet. Therefore, in this example, there is no dedicated line voltage or high voltage power supply for powering the electromagnetic field generator 400 . Instead, main power is low current high voltage power. The exemplary generator 400 includes a frequency generator 404 that generates the frequencies required to operate the generator 400 . In this example, the frequency may be, for example, about 637 kHz. The frequency is adjustable and can be changed based on the characteristics of the suction and/or dispensing device or other workpiece located in the magnetic field and heated.

In some examples, the frequency can also be adjusted based on the type of reagent and/or sample, including, for example, whether the contents of the aspiration and/or dispensing device were previously a blood sample or will be in an upcoming use. blood sample. For example, the frequency can be adjusted based on the amount of bound protein expected for a particular type of sample. Thus, for example, for "cleaner solutions" (ie, solutions where lower amounts of bound proteins or other organisms are expected to be carried over), the frequency/power may be reduced. The sample itself does not affect the heat rate or generation in the aspiration and/or dispensing device.

Furthermore, the frequency can also be adjusted if, for example, the test to be performed is particularly sensitive to carryover. In such instances, the frequency may be adjusted to maximize the amount of heat carried over for reduction and/or elimination. For example, if the assay is particularly sensitive to carryover, higher and/or maximum available power and heat generation can be used to reduce and/or eliminate carryover.

Additionally, in other examples, the frequency can be adjusted to use the lowest available heat for a particular heating/cleaning cycle to reduce material stress on the probe, shorten cycle time, and/or maximize energy efficiency. In some examples, power usage and/or frequency are adjusted based on the amount of pollutants being pumped. In such instances, higher power may be used for cleaning cycles involving a relatively greater amount of probe length to be cleaned. Also, in some instances, lower power can be used to clean smaller areas. In both types of examples, the cleaning time can be consistent even though the power used and the probe lengths cleaned will vary. Furthermore, in some instances, when, for example, a small area of the suction and/or dispensing device (e.g., probe) is to be cleaned and relatively higher power is used, the time spent cleaning and thus heating in the electromagnetic field can be reduced Time spent pumping and/or dispensing the device. In some instances, the aspiration and/or dispensing device is not subjected to heat levels near a critical temperature at which the material of the aspiration and/or dispensing device begins to exhibit heat-related problems. Furthermore, control of the frequency and thus the heat level can be used to reduce material stress, increase the service life of the suction and/or dispensing device and reduce failures. Also, in some instances, when less power is required in an induction heater (eg, in a coil), the frequency may be increased relative to nominal. This results in less strain on the semiconductor switch (eg, in the exemplary systems 400, 500, 600, 700 disclosed herein) when the drive frequency is higher than the resonant frequency because the switch is not "hard" against the potential. switch".

The exemplary generator 400 also includes a power controller 406 to control the flow of power from the main power supply 402 at the frequency generated by the frequency generator 404 . A square wave signal or waveform is used in this example, but other waveforms may be used including, for example, sinusoidal, triangular, or sawtooth waveforms. An exemplary input power may be about 450 watts.

The example generator 400 also includes a transformer 408 . Transformer 408 steps down the voltage and steps up the current. The transformer 408 also provides isolation between the resonant or tank tank 410 and the main power supply 402 . Transformer 408 also provides a means to electrically match tank circuit 400 to main power supply 402 and power controller 406 by amplifying or reducing the impedance of tank circuit 410 seen by main power supply 402 and power controller 406 so that generator 400 does not draw excessive current. In some examples, transformer 408 may have a turns ratio of approximately 5.45:1. Thus, in this embodiment, the current after transformer 408 is approximately 5.45 times the current before transformer 408, and the voltage after transformer 408 is reduced to 1/5.45.

Oscillating circuit 410 is a parallel inductance-resistor-capacitance (LRC) circuit comprising resistor 412 (the resistance of the system including the transmission line and the inherent resistance of inductance) and a parallel connected capacitor 420 having a value selected such that the oscillator circuit 410 resonates at the frequency of the frequency generator 404 . Capacitor 420 provides the capacitance required by the resonant circuit, and work coil 418 provides at least some of the inductance and resistance in tank circuit 410 . In this example, capacitor 420 is about 0.45 μF in parallel and work coil 418 has an inductance of about 1.4 μH. The oscillator circuit 410 further increases the current for the working coil 418 . Exemplary work coil 418 operates as disclosed above to generate an alternating magnetic field, which results in a magnetic field that opposes the magnetic field generated by the workpiece and thus raises the surface temperature of any workpiece located within work zone 422 inside work coil 418 . In this example, the current before the transformer is about 4.4A and the current after the transformer is about 24A. In this example, tank circuit 410 further increases the current to approximately 240A, resulting in a 53.4-fold increase in the total current at work coil 412 . Additionally, the exemplary work coil 418 can raise the surface temperature of the workpiece, such as raising the suction and/or dispensing device 0-100°C in less than 1 second, 0-300°C in 1-2 seconds, 0-300°C in 7 seconds The internal temperature rises to 700-800°C.

There are several design elements for optimizing the operation of the exemplary generator 400, including, for example, coil design and selection (inductance size, resistance value, small spacing between coil and workpiece), components to be heated (physical size, material composition), the amount of primary power available (voltage, current), desired heating rate, desired maximum temperature, and desired type of heating (through heating, surface heating). These factors affect the components used in the exemplary generator 400, including, for example, the nominal frequency generated at the frequency generator 404 (for heating the workpiece), the required capacitance (in Farads and kVAR), the oscillator circuit 410 The multiplier value (Q), the phase angle (φ) of the oscillator circuit 410 (integer power factor of cos(φ)=1), the ratio and location of the transformer 408, power supply design, and connection line selection (to minimize stray inductance and pressure drop).

In particular, the frequency for a particular workpiece depends on the desired or physical shell thickness of the workpiece, and the thickness depends on the workpiece's outer diameter (assuming but not limited to cylindrical cross-section), wall thickness, and material composition. Enclosure thickness is defined as, for example, the depth at which approximately 86% of the induced power is generated. The optimum depth for a tubular or cylindrical workpiece is defined by equation (1) below.

In equation (1), the shell thickness is represented by δ, t = wall thickness (m), d = tube diameter (m). Equation (1) can be solved for the case thickness, which can be used in Equation (2) below to calculate the frequency f.

In Equation 2, resistivity is represented by ρ (μΩm), and μ represents magnetic permeability (H/m). Equation (2) can be solved to determine the frequency f (Hz).

Selection of components for the oscillation circuit 410 depends on the desired frequency f (Hz), capacitance C (F) and inductance L (H), as shown in equation (3) below.

In addition, as shown in the following equation (4), it can be obtained via kilovolt-ampere reactive (kVAR), power (W), angular frequency ω (rad/s), capacitance C (F), voltage (V), current I (A), resistance R (Ω), inductance L (H) and/or sense resistance X _L (Ω) to control or manipulate the Q factor of the oscillation circuit 410 .

A higher Q value yields a smaller bandwidth, which is more difficult to tune to resonance, but provides higher current multiplication in the tank circuit 410 . Conversely, a smaller Q allows a larger bandwidth, which is easier to tune for resonance and is more tolerant to detuning, but provides lower current multiplication in the tank circuit 410 . After the components for the oscillating circuit have been selected, the impedance Z (Ω) of the circuit can be calculated and the turns ratio of the transformer 408 chosen so that it is properly matched and does not draw excessive current from the main power supply 402 . The impedance Z _eq (Ω) of the oscillating circuit depends on the angular frequency ω (rad/s), the capacitance C (F), the equivalent series resistance R _C (Ω) of the capacitor, the series resistance R _L (Ω) of the inductor, the inductance L (H), equivalent circuit resistance _Req (Ω), and equivalent circuit impedance X _eq (Ω), as shown in equations (5), (6) and (7) below.

The optimum transformer turns ratio Y _t depends on the voltage V _ps (V) of the power supply, the maximum current I _max (A) that can be safely drawn from the power supply and the impedance Z _eq (Ω) of the tank circuit, and as seen by the power supply The resistance R _ps (Ω), as shown below in equations (8) and (9).

The above equation describes the turns ratio of the transformer 408 that provides the maximum amount of power drawn from the power supply 402 . If a turns ratio greater than that shown in Equation 9 is selected, the current drawn from the main power supply 402 will be reduced and the overall power consumption of the generator 400 will be reduced.

FIG. 5 illustrates another exemplary circuit configuration for an electromagnetic field generator 500 that may be included in, for example, a medical diagnostic system or an automated pipetting system. Components similar to those described in other examples will not be repeatedly described in this example or subsequent examples, although the values of the components may be different. For example, current sources, frequencies, capacitors, etc. may have different values, but operate in a similar manner as disclosed above. The exemplary generator 500 of FIG. 5 includes a transformer having a greater than optimally selected turns ratio. In the present example shown in FIG. 5, the frequency generator 404 may generate a 643 kHz square wave. In this example, current source 506 , which includes aspects of main power supply 402 and power controller 406 of FIG. 4 , produces a current of approximately 3.3A. In this example, the first transformer 502 and the second transformer 504 together form a transformer with a turns ratio of about 16:1. Therefore, after the transformers 502, 504, the current multiplication number is 16 times. In this example, the current after the transformer is about 52.8A. In this example, tank circuit 410 further increases the current to about 160A, resulting in a total increase at work coil 412 of about 48 times. In this example, the total system power is reduced, but the draw to current source 506 is reduced to match the desired demand in this example.

FIG. 6 illustrates another exemplary circuit configuration for an electromagnetic field generator 600 that may be included in, for example, a medical diagnostic system or an automated pipetting system. The example generator 600 of FIG. 6 includes a controller 602 and one or more feedback loops 604 . Feedback loop 604 provides data to controller 604 regarding various metrics of generator 600, such as, for example, frequency, impedance, temperature, presence of suction and/or dispensing device 606 in the electromagnetic field of working coil 412, presence of Voltage readings and/or current readings at any point. The presence of the aspiration and/or dispensing device 606 may be detected by a change in temperature or load at the working coil 412 . In addition, as the arm 608 moves the aspiration and/or dispense device 606 up or down past the working coil 412, the physical characteristics of the aspiration and/or dispense device 606 can be changed to alter the temperature of the aspiration and/or dispense device 606 that is in the electromagnetic field and is thus inductively heated. The surface of the suction and/or dispensing device 606 . For example, the exemplary aspiration and/or dispense device 606 has a diameter that tapers toward the tip 610 (ie, is tapered). The optimum frequency to properly heat the tip 610 is different than the frequency required to properly heat the larger diameter portion of the aspiration and/or dispense device 606 . Accordingly, the controller 602 may adjust the frequency based on the data to vary the strength of the electromagnetic field to optimize the heating temperature of the aspiration and/or dispensing device 606 .

The controller 602 also acts as a calibrator, enabling the generator 600 to self-calibrate based on shifts in capacitance or impedance over time. Additionally, the controller 602 may also sense shorts and/or other problems with any of the components of the generator 600 or the interconnections between them.

FIG. 7 illustrates another exemplary circuit configuration for an electromagnetic field generator 700 that may be included in, for example, a medical diagnostic system or an automated pipetting system. The example generator 700 of FIG. 7 includes a step-up/step-down transformer 702 and a rectifier 704 coupled to the main power supply 402 . Step-up/step-down transformer 702 and rectifier 704 are separate components in some examples, and are integrally formed with power supply 402 in other examples. Stepping up/stepping down transformer 702 and rectifier 704 enables generator 700 to draw power from power supply 402 and process that power into a direct current (DC) signal with suitable voltage and current capabilities. Thus, the generator 700 can be coupled to a wall outlet in any country, and the step-up/step-down transformer 702 and rectifier 704 can be selected and/or adjusted to adjust to the power available from the wall outlet. Accordingly, transformer 702 and/or rectifier 704 may be selected such that the system does not draw excessive current from main power supply 402 . In some examples, stepping up/stepping down transformer 702 and rectifier 704 modifies the power to change the AC voltage supplied by power supply 402 to a DC voltage to have a voltage of 120V and a current of 10A and/or otherwise adjust the supplied voltage. power. The exemplary generator 700 also includes an additional feedback loop 706 to provide further data to the controller 602, such as, for example, current readings, voltage readings, or any other suitable data.

Although exemplary ways of implementing the generators 400, 500, 600, 700 have been illustrated in FIGS. 4-7, one or more of the elements, processes, and/or devices shown in FIGS. 4-7 may Combined, separated, rearranged, omitted, eliminated and/or effected in any other way. Additionally, the example frequency generator 402, power controller 406, current source 506, system controller 602, rectifier 704, and/or, more generally, the example generators 400, 500, 600, 700 of FIGS. 4-7, may Realized by hardware, software, firmware and/or any combination of hardware, software and/or firmware as part of a medical diagnostic device or as a separate induction heating cleaning device. Thus, for example, the example frequency generator 402, power controller 406, current source 506, system controller 602, rectifier 704 and/or, more generally, the example generators 400, 500, 600, 700 of FIGS. 4-7 Any device in the system can be implemented by one or more circuits, programmable processors, application-specific integrated circuits (ASICs), programmable logic devices (PLDs) and/or field-programmable logic devices (FPLDs), etc. When any device or system claims of the present invention are read to cover software and/or firmware implementations only, the exemplary frequency generator 402, power controller 406, current source 506, system controller 602 and/or rectifier 704 At least one of is thus expressly defined as comprising a tangible computer-readable medium, such as memory, DVD, CD, Blu-ray Disc, etc., storing software and/or firmware. Additionally, the example generators 400, 500, 600, 700 of FIGS. 4-7 may include one or more elements, processes, and/or devices in addition to or instead of those shown in FIGS. 4-7, and/or may More than one of any or all of the elements, procedures and devices shown are included.

FIG. 8 shows a schematic flow diagram representing an exemplary process that may be used to implement the devices and systems of FIGS. 1-7. In this example, the process includes a program executed by a processor, such as the processor 912 shown in the exemplary computer 9000 discussed below in connection with FIG. 9 . The program may be embodied as software stored on a tangible computer readable medium such as a CD-ROM, floppy disk, hard disk, digital versatile disk (DVD), Blu-ray disk, or memory associated with the processor 912, but the entire program and/or Or a portion of the program may alternatively be executed by a device other than the processor 912 and/or embodied as firmware or dedicated hardware. Furthermore, although the example procedure is described with reference to the flowchart shown in FIG. 8, many other methods of implementing the example systems and devices disclosed herein may alternatively be used. For example, the order of execution of the blocks may be changed, and/or some of the blocks described may be changed, eliminated, or combined.

As noted above, the example process of FIG. 8 can be implemented using coded instructions (e.g., computer readable instructions) stored on a tangible computer readable medium, such as a hard drive, flash memory, read only memory (ROM ), compact discs (CDs), digital versatile discs (DVDs), caches, random access memory (RAMs) and/or in which information may be stored for any duration (e.g., long-term, permanent, short-term, temporary buffered and/or information cache) any other storage medium. As used herein, the term "tangible computer readable medium" is expressly defined to include any type of computer readable memory and to exclude propagating signals. Additionally or alternatively, the example process of FIG. 8 may be implemented using coded instructions (e.g., computer readable instructions) stored on a non-transitory computer readable medium, such as a hard drive, Flash memory, read-only memory, compact disc, digital versatile disc, cache memory, random access memory and/or any other storage media. As used herein, the term "non-transitory computer-readable medium" is expressly defined to include any type of computer-readable memory and does not include propagating signals. As used herein, when the phrase "at least" is used as a transitional term in the preamble of a claim, "at least" is also open-ended like the term "comprises". Thus, a claim using "at least" as the transition term in its preamble may include elements in addition to those expressly recited in the claim.

FIG. 8 illustrates a process 800 for reducing carryover including, for example, denaturing and/or inactivating proteins and/or other biological material, sanitizing, cleaning, and the like. In some examples, process 800 includes preflushing or otherwise preconditioning a probe or other aspiration and/or dispensing device with, for example, one or more of the preflushes of FIGS. 2 and 3 (block 802 ). The example process 800 also includes generating an electromagnetic field (block 804). Exemplary electromagnetic fields may be generated by, for example, the coils 100, 204, 306, 412 of FIGS. 1-7 and/or the generators 400, 500, 600, 700 of FIGS. 4-7. In some examples, the electromagnetic field is an alternating electromagnetic field generated by an AC power source.

In the example process 800 of FIG. 8, the presence or absence of a probe is detected (block 806). If a probe is not detected, control remains at block 806 until a probe has been introduced into the generated electromagnetic field. When the probe has been introduced into the electromagnetic field, the example process 800 determines whether the electromagnetic field should be adjusted (block 808 ). For example, the controller 602 may sense that the size of the probe in the working coil 412 requires a different frequency to optimize the electromagnetic field and resulting induced heat, and the process 800 adjusts (block 810 ). When adjustments are not required or after adjustments have been made, process 800 continues and the probe is heated (block 812 ). During heating of the probe (block 812 ), the position of the probe may be adjusted (eg, raised or lowered) relative to the electromagnetic field and coil to change the portion of the probe that is subjected to the electromagnetic field and associated inductive heating. After the probe is heated for a desired temperature and/or duration to denature and/or inactivate any biological matter, one or more optional post-wash steps may be performed (block 814). For example, a post-rinse can wash carbonized proteins and/or other residues from the probe, a cool-rinse can reduce the temperature of the probe, and/or other post-treatments can be performed. The example process 800 ends (block 816) and the probe can be reused.

FIG. 9 is a block diagram of an example computer 900 capable of executing the process of FIG. 8 to implement the apparatus of FIGS. 1-7. Computer 900 may be, for example, a server, a personal computer, or any other type of computing device.

The system 900 of this example includes a processor 912 . For example, processor 912 may be implemented by one or more microprocessors or controllers from any desired family or manufacturer.

Processor 912 includes local memory 913 (eg, a cache) and communicates via bus 918 with main memory including volatile memory 914 and non-volatile memory 916 . Volatile memory 914 may be implemented by synchronous dynamic random access memory (SDRAM), dynamic random access memory (DRAM), RAMBUS dynamic random access memory (RDRAM), and/or any other type of random access memory device. Non-volatile memory 916 may be implemented by flash memory and/or any other desired type of memory device. Access to main memory 914, 916 is controlled by a memory controller.

Computer 900 also includes interface circuitry 920 . Interface circuit 920 may be implemented by any type of interface standard, such as Ethernet interface, Universal Serial Bus (USB), and/or PCI express interface.

One or more input devices 922 are connected to interface circuit 920 . Input device 922 allows a user to enter data and commands into processor 912 . The input means can be realized by eg keyboard, mouse, touch screen, touch pad, trackball, isopoint and/or voice recognition system.

One or more output devices 924 are also connected to interface circuit 920 . The output device 924 may be implemented, for example, by a display device (eg, a liquid crystal display, a cathode ray tube display (CRT), a printer, and/or speakers). Accordingly, interface circuit 920 typically includes a graphics driver card.

Interface circuitry 920 also includes communication devices, such as a modem or network interface card, to facilitate communication with external computers via network 926 (e.g., Ethernet connection, digital subscriber line (DSL), telephone line, coaxial cable, cellular telephone system, etc.) data.

Computer 900 also includes one or more mass storage devices 928 for storing software and data. Examples of such mass storage devices 928 include floppy disk drives, hard disk drives, compact disk drives, and digital versatile disk (DVD) drives.

Coded instructions 932 to implement process 800 of FIG. 8 may be stored in mass storage device 928, in volatile memory 914, in nonvolatile memory 916, and/or on a removable storage medium such as a CD or DVD.

From the above, it should be appreciated that the methods, apparatus, systems and articles of manufacture disclosed above may be used to inductively heat aspiration and/or dispensing devices in medical diagnostic instruments or automated pipetting systems. These examples enable heating of such suction and/or dispensing devices without requiring physical or electrical contact with the suction and/or dispensing device. The risk of electrical shorts is reduced and lower voltages can be used. Additionally, less heat is required to sterilize, denature or inactivate proteins and other biological matter and/or otherwise clean the aspiration and/or dispensing device. Accordingly, the time required for the exemplary processes disclosed herein is also reduced. Furthermore, the heat is controlled and spread evenly over the target surface, and it is not necessary to heat the entire suction and/or dispensing device. Furthermore, induction heating of the suction and/or dispensing device allows re-use of the device. Induction heating produces negligible solid waste and significantly less biohazardous waste. The exemplary systems and devices disclosed herein can be plugged into any electrical wall outlet and do not require a dedicated power cord for the electromagnetic field generator. Induction heating provides a safe, controllable, rapid and low incremental cost method for preventing and/or eliminating carryover or cross-contamination of proteins and/or other biological matter.

Although certain exemplary methods, apparatus, and articles of manufacture have been described herein, the scope of coverage of the invention is not limited thereto. On the contrary, this invention fully covers all methods, apparatus and articles of manufacture fairly falling within the scope of the present claims.

Claims (29)

1. A method comprising: generate an alternating electromagnetic field; introducing the suction and dispensing device into said electromagnetic field; and Using the electromagnetic field to inductively heat the aspiration and dispense device to at least denature or inactivate at least one of proteins or biological entities on the surface of the aspiration and dispense device. 2. The method of claim 1, further comprising rinsing the aspiration and dispense device prior to introducing the aspiration and dispense device into the electromagnetic field. 3. The method of claim 1, further comprising rinsing the aspiration and dispense device after inductively heating the aspiration and dispense device with the electromagnetic field. 4. The method of claim 4, wherein the flushing comprises: flushing with a cooling flush to reduce the temperature of the aspiration and dispensing device. 5. The method of claim 1, further comprising flushing the aspiration and dispense device during inductively heating the aspiration and dispense device with the electromagnetic field. 6. The method of claim 1, wherein generating the electromagnetic field comprises flowing an electrical current through a conductive medium with a frequency that is based on a diameter of the suction and dispense device. 7. The method of claim 6, wherein the conductive medium is a coil. 8. The method of claim 1, wherein generating the electromagnetic field comprises flowing an electrical current through a conductive medium with a frequency that is based on a thickness of a housing of the suction and dispense device. 9. The method of claim 8, further comprising: raising or lowering the suction and dispense device through the electromagnetic field to inductively heat the suction and dispense device along the length of the suction and dispense device device. 10. The method of claim 9, wherein the thickness of the housing varies along the length of the suction and/or dispensing device, and the method further comprises: raising or lowering the suction and dispensing device adjust the frequency. 11. The method of claim 1, further comprising inductively heating only a portion of the suction and dispense device. 12. The method of claim 1, wherein generating the alternating electromagnetic field comprises utilizing a standard wall electrical outlet. 13. The method of claim 1, further comprising: placing an irrigation cup between said aspiration and dispensing device and a conductive medium for generating said electromagnetic field; and The rinsing cup is used to prevent direct contact between the suction and dispensing device and the electrically conductive medium. 14. A system comprising: electromagnetic field generator; suction and dispensing devices to be introduced into an electromagnetic field and to be inductively heated by the electromagnetic field; and A rinse cup interposed between the electromagnetic field generator and the aspiration and dispensing device to prevent direct contact therebetween. 15. The system of claim 14, further comprising a flusher to flush the aspiration and dispense device prior to introducing the aspiration and dispense device into the electromagnetic field. 16. The system of claim 14, further comprising a flusher to flush the aspiration and dispense device after inductively heating the aspiration and dispense device with the electromagnetic field. 17. The system of claim 16, wherein the flusher flushes with a cooling flush to reduce the temperature of the aspiration and dispensing device. 18. The system according to claim 14, wherein the electromagnetic field generator comprises a frequency generator and a conductive medium, the frequency generator is used to generate a variable-frequency current flowing through the conductive medium, wherein the Frequency is based on the diameter of the aspiration and dispensing device. 19. The system of claim 18, wherein the conductive medium is a coil. 20. The system according to claim 14, wherein the electromagnetic field generator comprises a frequency generator and a conductive medium, the frequency generator is used to generate a variable frequency current flowing through the conductive medium, wherein the frequency Depending on the thickness of the housing of the suction and dispensing device. 21. The system of claim 20, further comprising an arm to raise or lower the suction and dispense device through the electromagnetic field to inductively heat the suction and dispense device along the length of the suction and dispense device. and dispensing device. 22. The system of claim 21 , wherein the thickness of the housing varies along the length of the suction and dispense device, and wherein the electromagnetic field generator comprises a frequency generator at the Adjust the frequency when the suction and dispensing device is raised or lowered. 23. The system of claim 14, wherein the electromagnetic field inductively heats only a portion of the aspiration and dispense device. 24. The system of claim 14, wherein a surface of the aspiration and dispense device is heated to denature at least one of proteins or biological entities on the surface. 25. The system of claim 14, further comprising a controller and a feedback loop, the feedback loop providing data to the controller, the data including frequency, impedance, presence of the aspiration and dispensing device in the electromagnetic field , a voltage reading, or a current reading, and the controller varies the frequency based on the data to vary the strength of the electromagnetic field, thereby varying the heating temperature of the aspiration and dispense device. 26. The system of claim 14, wherein the aspiration and dispense device has no electrical connectors coupled to a surface of the aspiration and dispense device, and the aspiration and dispense device is electrically insulated. 27. A tangible machine-readable medium storing instructions which, when executed, cause a machine to: generate an alternating electromagnetic field; introducing the suction and dispensing device into said electromagnetic field; and Using the electromagnetic field to inductively heat the aspiration and dispense device to at least denature or inactivate at least one of proteins or biological entities on the surface of the aspiration and dispense device. 28. The medium of claim 27, wherein the electromagnetic field is generated by causing the machine to flow an electrical current through a conductive medium with a frequency based on the diameter of the suction and dispense device. 29. The medium of claim 27, wherein the electromagnetic field is generated by causing the machine to flow an electric current through a conductive medium with a frequency based on the thickness of the housing of the suction and dispense device.